University of Minnesota
March 25, 2013
Anthony Weinhaus holds plastinated brain slices. Foreground: plastinated heart/lungs set.
U lab is among a handful to 'plastinate' human organs
If you've seen the Body Worlds exhibit at the Minnesota Science Museum, you know how well the modern preservation technique called plastination works.
Organs are preserved in silicone or polyester, which solidifies them and protects them from decay while keeping their shape and appearance.
Plastination also renders organs or slices of organs—notably the brain—less fragile. Anatomy students can just pick them up and examine them closely, glove- and fume-free.
University of Minnesota anatomy students can, that is. The U has one of only about a dozen labs in the country that perform plastination, and for educational—not public or commercial—and limited research purposes only.
"Plastinating is a way to maintain difficult structures and pathologies," says Anthony Weinhaus, director of the Program in Human Anatomy Education. "For example, we have a dissection of the 12 cranial nerves and the Circle of Willis, an arterial structure deep in the brain where blood circulates like cars in a roundabout. We also have hearts with pacemakers and stents— we don't see these very often."
Tour of a broken heart
The technique was pioneered in the 1970s by German anatomist Gunther von Hagens, whose work is on display in Body Worlds. Now Paul Hill, a staff member with the U's Anatomy Bequest Program, carries on the legacy by plastinating organs of donors who have given written permission. Weinhaus uses the specimens, or "plastinates," to teach courses, including the human gross anatomy lab required of students of anatomy, medicine, and other health professions.
Paul Hill holds two plastinated hearts: one (r.) normal, the other enlarged and with severe defects.
He finds one plastinated heart particularly intriguing. A hole between the two atria allowed oxygen-poor blood returning from the body to mix with oxygen-rich blood fresh from the lungs, so the patient suffered from chronic lack of oxygen. But worse was the hole connecting the right and left ventricles.
"They acted almost like one big ventricle pumping simultaneously to the lungs and aorta," Weinhaus says. "While [normally only the left] ventricle pumps under huge pressure, here both had high pressure. It caused chronic pulmonary (lung) hypertension and [could have ruptured] pulmonary capillaries."
The heart's pulmonary trunk—the vessel exiting the right ventricle—had dilated greatly to reduce the pressure. Its owner was one of only four cases known where the patient lived to adulthood without surgery, Weinhaus says. Now, babies born with such defects are routinely corrected.
Plastination in context
At the U, plastination starts with organs dissected by students and fixed in formalin. They are then cleansed in water and dehydrated in acetone. Later, a vacuum removes the acetone while drawing a liquid silicone or polyester polymer into the tissue, and a catalyst is added to harden the polymer. The process can take up to several months.
Model showing the Circle of Willis, an arterial "roundabout" deep in the brain.
Hill, who has produced some 50 plastinations so far, graduated from the U's Mortuary Science Program.
"One thing I learned in the anatomy course in mortuary science was how much variation there is in anatomy," he says. "For example some people have four, rather than three, branches of the aorta." Hill was brought in to head the plastination lab in 2009.
The lab is part of the U's Anatomy Bequest Program. But plastinations are just one way donors' bodies educate more than 3,000 people a year in Jackson Hall, says Angela McArthur, program director.
"The Department of Emergency Medicine teaches interventions using whole body donors," she says. "Also, training labs teach doctors, nurses, half of Minnesota's paramedics, and other health care practitioners."
For Weinhaus, it comes down to the wonder of the human body and teaching its anatomy with all the techniques available.
"Our courses are active learning," he says. "[It's great] in anatomy, where students see for themselves the body's complexity and wonder."
Contact the writer at firstname.lastname@example.org